1,070 research outputs found
R-Process Nucleosynthesis In Neutrino-Driven Winds From A Typical Neutron Star With M = 1.4 Msun
We study the effects of the outer boundary conditions in neutrino-driven
winds on the r-process nucleosynthesis. We perform numerical simulations of
hydrodynamics of neutrino-driven winds and nuclear reaction network
calculations of the r-process. As an outer boundary condition of hydrodynamic
calculations, we set a pressure upon the outermost layer of the wind, which is
approaching toward the shock wall. Varying the boundary pressure, we obtain
various asymptotic thermal temperature of expanding material in the
neutrino-driven winds for resulting nucleosynthesis. We find that the
asymptotic temperature slightly lower than those used in the previous studies
of the neutrino-driven winds can lead to a successful r-process abundance
pattern, which is in a reasonable agreement with the solar system r-process
abundance pattern even for the typical proto-neutron star mass Mns ~ 1.4 Msun.
A slightly lower asymptotic temperature reduces the charged particle reaction
rates and the resulting amount of seed elements and lead to a high
neutron-to-seed ratio for successful r-process. This is a new idea which is
different from the previous models of neutrino-driven winds from very massive
(Mns ~ 2.0 Msun) and compact (Rns ~ 10 km) neutron star to get a short
expansion time and a high entropy for a successful r-process abundance pattern.
Although such a large mass is sometimes criticized from observational facts on
a neutron star mass, we dissolve this criticism by reconsidering the boundary
condition of the wind. We also explore the relation between the boundary
condition and neutron star mass, which is related to the progenitor mass, for
successful r-process.Comment: 14 pages, 2 figure
Microscopic Theory of Skyrmions in Quantum Hall Ferromagnets
We present a microscopic theory of skyrmions in the monolayer quantum Hall
ferromagnet. It is a peculiar feature of the system that the number density and
the spin density are entangled intrinsically as dictated by the W
algebra. The skyrmion and antiskyrmion states are constructed as W-rotated states of the hole-excited and electron-excited states,
respectively. They are spin textures accompanied with density modulation that
decreases the Coulomb energy. We calculate their excitation energy as a
function of the Zeeman gap and compared the result with experimental data.Comment: 15 pages (to be published in PRB
Comparison of the Effects of Two Types of Stretching Warm Ups for Rehabilitation
This pilot study compares the effects of static therapeutic trunk stretching using an unstable flex chair, a stretching bench and a stretching stick on physical fitness with those of a general Japanese style of static stretching. The participants underwent physical fitness tests. Before and after warming up using a general Japanese style of stretching and trunk treatment stretching. Twenty-three healthy college students (age, 20.7 ± 1.2 years; height, 165.3 ± 7.6 cm; weight, 59.0 ± 9.7 kg; BMI 21.4 ± 2.3) were enrolled in this study. The physical fitness test assesses grip strength, sit-ups, eyes-closed single-leg stance, sit-and-reach flexibility, six-minute walk, and ten-meter obstacle course. The participants performed vertical jump, forward standing flexion measured using the analog flexion meter, thoracolumbar extension, horizontal flexure, deep forward bow. These results suggest that trunk stretching improves flexibility, walking ability, endurance and explosive power more effectively than the general Japanese style of stretching. Three static trunk stretches can improve flexibility, walking ability, endurance and explosive power. Trunk treatment stretching before physical activity might reduce the incidence of injury and improve the physical performance of individuals who participate in exercise, athletes and injured persons undergoing rehabilitation.ArticleBAOJ Medical and nursing.1(1):003(2015)journal articl
A case study of health education from Nagano prefecture in Japan: The relationship between health education and medical expenses
Background: Health promotion is not only the responsibility of the health sector, but extends from healthy lifestyles to wellbeing. We developed an active health program acquired ISO9001 (the International Organization for Standardization) in 2014. This health education program desired to Asian countries in cooperation with Asian Universities with the aim of increasing the health longevity of their populations.Methods: The authors implemented a 10-month health program from May 2010 to Feb 2011 in Minowa town, Nagano prefecture, Japan. Participants of a health education group (HEG) in Minowa town included 41 elderly (age: 63.4 ± 5.9) individuals; 6 residents of Nagano city (aged 59.4 ± 7.9) acted as a control group (CG).Results: The HEG participants showed significant improvement in weight, BMI, anthropometric measurements, systolic blood pressure, diastolic blood pressure, physical fitness factors including sit-ups, sit-and-reach flexibility, eyes-open single-leg stance, 10 m obstacle walk and 6 min walk, LDL, and brain function as reflected in response time and error rates for go/no-go tasks. In contrast, CG had no significant differences in any items before and after the health education program period. Systolic blood pressure, sit-and-reach flexibility and 10 m obstacle walk of HEG participants showed a significant improvement compared to those of the CG. Medical expenses of HEG participants were significantly reduced for the 1st year and 2nd year after the health education program compared to those of the non-participants.Conclusion: The systolic blood pressure, sit-and-reach flexibility and 10 m obstacle walk of HEG participants showed a significant improvement compared to those of the CG. Medical expenses of HEG participants were significantly reduced during health education and 1st and 2nd years after the health education program compared to those of non-participants.ArticleJournal of Community Medicine & Health Education.7(3):529(2017)journal articl
In vitro fibrin clot formation and fibrinolysis using heterozygous plasma fibrinogen from gamma Asn319, Asp320 deletion dysfibrinogen, Otsu I
ArticleTHROMBOSIS RESEARCH. 118(5): 651-661 (2006)journal articl
Moderate exercise improves cognitive performance and decreases cortical activation in the go/no-go task
Background: A lot of studies have reported that physical activity has a beneficial influence not only on physical and mental disorders but also on cognitive and brain function. Performance of a go/no-go task improves after exercise. However, few studies have compared neural activity in a go/no-go task performed before and after exercise to identify brain regions that may respond to exercise and underlie this result. Therefore, the purpose of this study was to examine the brain blood flow and compare the cortical activation pattern during a go/no-go task performed before and after exercise.Method: Fifteen healthy subjects performed a go/no-go task before and after exercise. Functional near-infrared spectroscopy (fNIRS) was used to measure oxygenated hemoglobin concentration at 44 locations over both hemispheres. The exercise was of moderate intensity, defined as 50% of peak oxygen uptake.Result: The reaction time on the go/no-go task was significantly faster after exercise than before. The oxygenated hemoglobin concentration quantified across the whole brain was lower after exercise, and this was the case for go trials and no-go trials. In go trials, the oxygenated hemoglobin concentration in dorsolateral prefrontal cortex and supplementary motor area were significantly lower after exercise.Conclusion: These results suggest that the dorsolateral prefrontal cortex and supplementary motor area had lower activity in go trials in the go/no-go task performed after exercise than in go trials in the go/no-go task performed before exercise.ArticleBAOJ Medical and nursing.1(1):002(2015)journal articl
Nucleosynthesis in Baryon-Rich Outflows Associated With Gamma-Ray Bursts
Robust generation of gamma-ray bursts (GRBs) implies the formation of
outflows with very low baryon loads and highly relativistic velocities, but
more baryon-rich, slower outflows are also likely to occur in most GRB central
engine scenarios, either as ``circum-jet winds'' or ``failed GRBs''. Here we
study the possibility of nucleosynthesis within such baryon-rich outflows by
conducting detailed reaction network calculations in the framework of the basic
fireball model. It is shown that high baryon load fireballs attaining mildly
relativistic velocities can synthesize appreciable quantities of heavy neutron
capture elements with masses up to the platinum peak and beyond. Small but
interesting amounts of light elements such as deuterium and boron can also be
produced. Depending on the neutron excess and baryon load, the combination of
high entropy, rapid initial expansion and gradual expansion at later times can
cause the reaction flow to reach the fission regime, and its path can be
intermediate between those of the - and -processes (``-process''). The
nucleosynthetic signature of these outflows may be observable in the companion
stars of black hole binary systems and in the most metal-poor stars,
potentially offering an important probe of the inner conditions of the GRB
source. Contribution to the solar abundances for some heavy elements may also
be possible. The prospects for further developments in various directions are
discussed.Comment: ApJ, in press; 11 pages, 3 figure
Geometrical Effects of Baryon Density Inhomogeneities on Primordial Nucleosynthesis
We discuss effects of fluctuation geometry on primordial nucleosynthesis. For
the first time we consider condensed cylinder and cylindrical-shell fluctuation
geometries in addition to condensed spheres and spherical shells. We find that
a cylindrical shell geometry allows for an appreciably higher baryonic
contribution to be the closure density (\Omega_b h_{50}^2 \la 0.2) than that
allowed in spherical inhomogeneous or standard homogeneous big bang models.
This result, which is contrary to some other recent studies, is due to both
geometry and recently revised estimates of the uncertainties in the
observationally inferred primordial light-element abundances. We also find that
inhomogeneous primordial nucleosynthesis in the cylindrical shell geometry can
lead to significant Be and B production. In particular, a primordial beryllium
abundance as high as [Be] = 12 + log(Be/H) is possible while still
satisfying all of the light-element abundance constraints.Comment: Latex, 20 pages + 11 figures(not included). Entire ps file with
embedded figures available via anonymous ftp at
ftp://genova.mtk.nao.ac.jp/pub/prepri/bbgeomet.ps.g
Analysis of fibrinogen variants at gamma 387Ile shows that the side chain of gamma 387 and the tertiary structure of the gamma C-terminal tail are important not only for assembly and secretion of fibrinogen but also for lateral aggregation of protofibrils and XIIIa-catalyzed gamma-gamma dimer formation
This research was originally published in Blood. Author(s).Kani, S; Terasawa, F; Yamauchi, K; Tozuka, M; Okumura, N. Title. Blood. 2006;108:1887-1894. © by the American Society of Hematology.ArticleBLOOD. 108(6): 1887-1894 (2006)journal articl
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